Operation tool for fluid injector using multi-microneedle device

ABSTRACT

An operation tool for a fluid injector includes a selective movement mechanism which moves the fluid injector between a first protruding position and a second protruding position in a housing of an outer cylinder. When the fluid injector is at the first protruding position, microneedles of a multi-microneedle device are protruded out to a first distance from the first open end. When the fluid injector is at the second protruding position to discharge a fluid via the microneedles, the microneedles are protruded out to a second distance from the first open end, which is shorter than the first distance. The selective movement mechanism includes a rotational-linear movement conversion mechanism which moves the fluid injector between the first and second protruding positions along a longitudinal center line of the outer cylinder based on a direction and an amount of rotation of the outer cylinder relative to the fluid injector.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of International ApplicationNo. PCT/JP2013/071722, filed Aug. 9, 2013, which is based upon andclaims the benefits of priority to Japanese Application No. 2012-229581,filed Oct. 17, 2012. The entire contents of these applications areincorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to an instrument for operating a fluidinjector that uses a multi-microneedle device.

Discussion of the Background

Fluid injectors which use a multi-microneedle device are well known, forexample, in the medical field. Such a fluid injector is known as asyringe in the medical field.

A fluid injector is provided with a fluid retention barrel (syringebarrel of a syringe) which includes a long fluid retention space thatcan retain a given amount of fluid (e.g., medicinal solution in themedical field), a fluid outlet nozzle which is arranged at an end in alongitudinal direction of the fluid retention space and able todischarge the fluid from the fluid retention space, and a fluidretention space inlet opening which is arranged at the other end in alongitudinal direction of the fluid retention space. The fluid injectoris further provided with a piston member which is slidably assembledinto the fluid retention space of the fluid retention barrel along acenter line in the longitudinal direction via the fluid retention spaceinlet opening.

It is considered recently in the medical field to use amulti-microneedle device, in place of a single injection needle wellknown in the medical field, for conducting intradermal injection, withthe device being mounted to the fluid outlet nozzle of the injectionbarrel of a conventional syringe. The multi-microneedle device isprovided with a body that is formed with an outlet nozzle mountingnozzle which is detachably mounted to a fluid outlet nozzle of a syringebarrel to discharge a fluid (medicinal solution in the medical field),and a fluid retention space which temporarily retains the fluid that hasbeen discharged to the outlet nozzle mounting nozzle from the fluidoutlet nozzle of the syringe barrel by the pressing force of the pistonmember of the syringe. The multi-microneedle device is further providedwith a plurality of microneedles which are arranged on a plane of thebody, the plane being located on an opposite side of the outlet nozzlemounting nozzle, being intervened by the fluid retention space.

The plane of the body functions as a skin contact surface. Each of theplurality of microneedles has a microscopic fluid injection channelwhich is extended from a base end on the plane to a tip that is apartfrom the plane. In each of the plurality of the microneedles, the lengthbetween the base end and the tip (i.e. the height of each microneedle)is set so as to fall within a range of the thickness of a skin tissue,against which the microneedles are used, of an organism (e.g., any humanbeing) possessing the skin tissue.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, an operation tool fora fluid injector, includes an outer cylinder having a first open end, asecond open end, and a housing extended between the first open end andthe second open end, the housing being formed such that a fluid injectorhaving a multi-microneedle device is movable in the housing along alongitudinal center line of the fluid injector, and a selective movementmechanism which moves the fluid injector between a first protrudingposition and a second protruding position in the housing of the outercylinder. The selective movement mechanism is structured such that, whenthe fluid injector is at the first protruding position, microneedles ofthe multi-microneedle device is protruded out to a first distance fromthe first open end, and that when the fluid injector is at the secondprotruding position to discharge a fluid from the fluid injector via themicroneedles, the microneedles are protruded out to a second distancefrom the first open end, the second distance being shorter than thefirst distance. The selective movement mechanism includes arotational-linear movement conversion mechanism which is interposedbetween the outer cylinder and the fluid injector, and moves the fluidinjector between the first protruding position and the second protrudingposition along a longitudinal center line of the outer cylinder based ona direction and an amount of rotation of the outer cylinder relative tothe fluid injector.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 is a schematic vertical cross-sectional view illustrating anoperation tool according to an embodiment, for a fluid injector thatuses a multi-microneedle device, the view specifically illustrating afluid injector that uses a multi-microneedle device, with a plurality ofmicroneedles of the multi-microneedle being arranged at a firstprotruding position, in an outer cylinder of the operation tool;

FIG. 2 is a schematic vertical cross-sectional view illustrating theoperation tool according to the embodiment, for a fluid injector thatuses a multi-microneedle device, the view specifically illustrating afluid injector that uses a multi-microneedle device, with the pluralityof microneedles of the multi-microneedle being arranged at a secondprotruding position, in the outer cylinder of the operation tool;

FIG. 3 is a schematic vertical cross-sectional view illustrating anoperation tool according to a modification of the embodiment, for afluid injector that uses a multi-microneedle device, the viewspecifically illustrating a fluid injector that uses a multi-microneedledevice, with a plurality of microneedles of the multi-microneedle beingarranged at a first protruding position, in an outer cylinder of theoperation tool; and

FIG. 4 is a schematic vertical cross-sectional view illustrating theoperation tool according to the modification of the embodiment, for afluid injector that uses a multi-microneedle device, the viewspecifically illustrating a fluid injector that uses a multi-microneedledevice, with the plurality of microneedles of the multi-microneedlebeing arranged at a second protruding position, in the outer cylinder ofthe operation tool.

DESCRIPTION OF THE EMBODIMENTS

The embodiments will now be described with reference to the accompanyingdrawings, wherein like reference numerals designate corresponding oridentical elements throughout the various drawings.

First Embodiment

With reference to FIGS. 1 and 2, hereinafter is schematically describeda configuration of an operation tool 14 according to an embodiment, fora fluid injector 12 that uses a multi-microneedle device 10.

The fluid injector 12 using the multi-microneedle device 10 which isoperated by the operation tool 14 according to the embodiment isrecently considered to be used, for example, in the medical field as asyringe.

The fluid injector 12 is provided with a fluid retention barrel 12 b(syringe barrel of a syringe) which includes a long fluid retentionspace that can retain a given amount of a fluid (e.g., medicinalsolution in the medical field), a fluid outlet nozzle 12 a which islocated at a longitudinal end of the fluid retention space and enablesdischarge of the fluid from the fluid retention space, and a fluidretention space inlet opening which is located at the other longitudinalend of the fluid retention space. The fluid injector 12 is furtherprovided with a piston member 12 c which is slidably assembled into thefluid retention space of the fluid retention barrel 12 b along thelongitudinal center line via the fluid retention space inlet opening.

It is considered recently in the medical field to use themulti-microneedle device 10, in place of a single injection needle wellknown in the medical field, for intradermal injection, with the devicebeing mounted to the fluid outlet nozzle of the injection barrel of aconventional syringe.

The multi-microneedle device 10 is provided with a body 10 b that isformed with: an outlet nozzle mounting nozzle 10 a which is detachablymounted to the fluid outlet nozzle 12 a of the fluid retention barrel 12b of the fluid injector 12 (the syringe barrel of a syringe) todischarge a fluid (medicinal solution in the medical field); and a fluidretention space which temporarily retains the fluid that has beendischarged to the outlet nozzle mounting nozzle 10 a from the fluidoutlet nozzle 12 a of the fluid retention barrel 12 b by the pressingforce of the piston member 12 c of the fluid injector 12. Themulti-microneedle device 10 is further provided with a plurality ofmicroneedles 10 c which are arranged on a surface (a plane in thepresent embodiment) of the body 10 b, the surface being located on anopposite side of the outlet nozzle mounting nozzle 10 a, beingintervened by the fluid retention space.

The multi-microneedle device 10 can be fabricated, for example, byapplying an etching process that uses a known photolithography method toa silicon substrate. Further, using the multi-microneedle device made ofsilicon as an original plate, an inverted replicated plate can be formedusing electroforming, and using the replicated plate, amulti-microneedle device made of a resin can be fabricated.

Preferably, at least the plurality of microneedles 10 c of themulti-microneedle device 10 are formed of a biocompatible material. Morepreferably, the multi-microneedle device 10 as a whole is formed of abiocompatible material. Such biocompatible materials include: metal thatcontains stainless steel, titanium, manganese, and the like; resins thatcontain medical silicone, polylactic acid, polyglycolic acid,polycarbonate, and the like; and inorganic materials, such as silicon.

The biocompatible resin materials as mentioned above can be subjected toa known molding technique, such as injection molding, imprinting, hotembossing, or the like, and processed into at least the plurality ofmicroneedles 10 c of the multi-microneedle device 10, or into the entiremulti-microneedle device 10.

Each of the plurality of microneedles 10 c has a microscopic fluidinjection channel which extends from a base end on the plane to a tipthat is apart from the plane. In each of the plurality of themicroneedles 10 c, the length between the base end and the tip, i.e. theheight of each microneedle 10 c, is set so as to fall within a range ofthe thickness of the skin tissue of an organism (e.g., any human being)possessing the skin tissue that is a target of using the needles,preferably within a range of the thickness of the skin tissue notincluding nerves. Specifically, it is preferable that the height of eachmicroneedle 10 c is set within a range of 100 μm to 2000 μm.

The overall shape of each of the plurality of microneedles 10 c may be acone shape including a circular cone or a pyramid, or may be a circularcolumnar or square columnar shape with its tip portion being in aconical or pyramidal shape. The microscopic fluid discharge channel canbe formed in each of the plurality of microneedles 10 c through a knownmicrohole drilling process by means of, for example, a micro drill, alaser beam, or the like.

The plurality of microneedles 10 c can be arrayed on the plane of thebody 10 b in a grid-like, concentric or random manner, or the like,according to the purpose of use.

The operation tool 14 according to the present embodiment is providedwith an outer cylinder 16 that includes a one-end opening 16 a, another-end opening 16 b, and a fluid injector housing space 16 c which isextended between the one-end opening 16 a and the other-end opening 16b, and holds the fluid injector 12 that uses the multi-microneedledevice 10 so as to be movable along a longitudinal center line of thefluid injector 12.

The operation tool 14 according to the present embodiment is furtherprovided with a selective movement mechanism 18 that moves the fluidinjector 12 between a first protruding position and a second protrudingposition in the injector housing space 16 c of the outer cylinder 16.

At the first protruding position, the fluid injector 12 is able to havethe microneedles 10 c of the multi-microneedle device 10, as shown inFIG. 1, out to an external space by a first distance from the one-endopening 16 a of the outer cylinder 16.

At the second protruding position, the fluid injector 12 is able to havethe microneedles 10 c of the multi-microneedle device 10, as shown inFIG. 2, out to an external space by a second distance, which is shorterthan the first distance mentioned above, from the one-end opening 16 aof the outer cylinder 16.

In the operation tool 14 according to the present embodiment, the fluidis discharged at the second position from the fluid injector 12 via theplurality of microneedles 10 c of the multi-microneedle device 10.

In the present embodiment, the outer cylinder 16 has one-end face inwhich the one-end opening 16 a is open, the one-end face functioning asa skin contact surface 16 d. It is preferable that the skin contactsurface 16 d is processed so as to be slidable relative to the surfaceof the skin of an organism without generating a large frictional force.

The selective mechanism 18 of the operation tool 14 according to thepresent embodiment includes a rotational-linear movement conversionmechanism 20 which is interposed between the outer cylinder 16 and thefluid injector 12 to move the fluid injector 12 between the firstposition shown in FIG. 1 and the second position shown in FIG. 2 alongthe longitudinal center line of the outer cylinder 16, in conformitywith the direction and amount of the rotation of the outer cylinder 16relative to the fluid injector 12.

In the present embodiment, the rotational-linear movement conversionmechanism 20 includes an internal threaded portion 20 a which isprovided to an inner surface of a peripheral wall of the outer cylinder16, and an external threaded portion 20 b which is provided to the fluidinjector 12 for threadable engagement with the internal threaded portion20 a of the outer cylinder 16.

In the present embodiment, the internal threaded portion 20 a can beintegrally formed with the peripheral wall of the outer cylinder 16.

More specifically, the selective movement mechanism 18 is provided witha cylindrical intermediate member 18 a having a one-end opening and another-end opening, and arranged between an outer peripheral wall of theouter cylinder 16 and an outer peripheral wall of the fluid retentionbarrel 12 b of the fluid injector 12 (syringe barrel of a syringe) thatis accompanied by the multi-microneedle device 10. The one-end openingof the intermediate member 18 a is fixed with an outer peripheralsurface of the body 10 b of the multi-microneedle device 10 of the fluidinjector 12. The fluid injector 12, which is connected to themulti-microneedle device 10, is housed in a columnar space extendingfrom the one-end opening to the other-end opening of the intermediatemember 18 a. The intermediate member 18 a is permitted to be movable inthe fluid injector housing space 16 c of the outer cylinder 16 togetherwith the fluid injector 12, which is accompanied by themulti-microneedle device 10, relative to the longitudinal center line ofthe outer cylinder 16. The intermediate member 18 a has an outerperipheral wall which is provided with the external threaded portion 20b. The external threaded member 20 b can be integrally formed into theouter peripheral wall of the intermediate member 16 a.

The body 10 b of the multi-microneedle device 10 can be formedseparately from the intermediate member 18 a, followed by fixing thebody 10 b of the multi-microneedle device 10 to the intermediate member18 a by a known fixing structure including, for example, an adhesive, asnap engagement, or a fixing screw. Alternatively, the multi-microneedledevice 10 and the intermediate member 18 a may be formed concurrently inan integrated manner.

Specifically, the external threaded portion 20 b of the presentembodiment is provided to the outer peripheral wall of the fluidinjector 12 via the intermediate member 18 a and the multi-microneedledevice 10.

The peripheral wall of the outer cylinder 16 has an outer surface whichis provided with a rotational operation member 16 e at a positiondistanced from the one-end opening 16 a toward the other-end opening 16b. The rotational operation member 16 e assists the operation forrotating the outer cylinder 16 relative to the fluid injector 12, aboutthe longitudinal center line of the outer cylinder 16.

In the present embodiment, the operation tool 14 is further providedwith a fluid injector retention cylinder 22 which is disposed in aportion of the outer surface of the peripheral wall of the outercylinder 16, the portion being distanced from the one-end opening 16 atoward the other-end opening 16 b of the outer cylinder 16 (a portionfurther distanced toward the other-end opening 16 b than the rotationaloperation member 16 d in the present embodiment). The fluid injectorretention cylinder 22 is permitted to be rotatable together with thefluid injector 12 about the longitudinal center line of the outercylinder 16 and also movable in a direction along the longitudinalcenter line, relative to the outer surface of the peripheral wall of theouter cylinder 16.

More specifically, the fluid injector 12 and the intermediate member 18a are further protruded outward along the longitudinal center line ofthe outer cylinder 16 than the other-end opening 16 b of the outercylinder 16. Similar to the fluid injector 12 and the intermediatemember 18 a, the fluid injector retention cylinder 22 is also furtherprotruded outward along the longitudinal center line of the outercylinder 16 than the other-end opening 16 b of the outer cylinder 16.

The intermediate member 18 a has an outer peripheral surface from whichat least one engagement projection 18 b is projected radially outwardrelative to the longitudinal center line of the fluid injector 12, beingpositioned in the vicinity of an end face on an opposite side of themulti-microneedle device 10 b.

The fluid injector retention cylinder 22 has an end face on an oppositeside of the outer cylinder 16, the end face being formed with at leastone fitting groove 22 a extended along the longitudinal center line ofthe fluid injector retention cylinder 22. As shown in FIG. 1, the atleast one engagement projection 18 b of the intermediate member 18 a isfitted to the at least one fitting groove 22 a of the fluid injectorretention cylinder 22. Accordingly, the fluid injector retentioncylinder 22 is made movable relative to the outer cylinder 16 along thelongitudinal center line of the outer cylinder 16 and also rotatableabout the longitudinal center line of the outer cylinder 16, integrallywith the intermediate member 18 a and the fluid injector 12.

The fluid retention barrel 12 b of the fluid injector 12 (syringe barrelof a syringe) connected to the multi-microneedle device 10 has an otherend portion which is protruded, together with the piston member 12 c,into an external space from the other-end opening of the intermediatemember 18 a.

In the present embodiment, it is preferable that each of the fluidinjector retention cylinder 22, the outer cylinder 16, the intermediatemember 18 a, and the fluid retention barrel 12 b of the fluid injector12 (syringe barrel of a syringe) is formed of a transparent material soas to enable visual recognition of the amount of a fluid (medicinalsolution in the medical field) retained by the fluid retention barrel 12b, from outside the fluid injector retention cylinder 22 and the outercylinder 16. Each of the fluid injector retention cylinder 22 and theouter cylinder 16 may be formed of a transparent material only in aportion of the outer peripheral wall that corresponds to the fluidretention barrel 12 b of the fluid injector 12.

Referring now to FIGS. 1 and 2, hereinafter is described a procedure ofinjecting a fluid (e.g., medicinal solution) retained by the fluidinjector 12, which uses the multi-microneedle device 10, into a desiredportion of a skin tissue of the exposed skin of an organism (e.g., humanbeing in the present embodiment) by operating the fluid injector 12 bymeans of the operation tool 14 which is based on the foregoingembodiment.

First, a user of the operation tool 14, which is based on the foregoingembodiment, holds the fluid injector retention cylinder 22 anddetachably mounts the fluid outlet nozzle 12 a of the fluid retentionbarrel 12 b of the fluid injector 12 to the outlet nozzle mountingnozzle 10 a of the multi-microneedle device 10. This mounting isconducted while the multi-microneedle device 10 is located at the firstposition, as shown in FIG. 1, by the rotation-linear movement conversionmechanism 20 of the selective movement mechanism 18.

In this case, the plurality of microneedles 10 c of themulti-microneedle device 10 which is located at the first position asmentioned above can be protected by a cap, not shown, from breakage thatwould be caused by an external force. The cap is detachably providedover a one-end portion in which the one-end opening 16 a is open in theouter surface of the peripheral wall of the outer cylinder 16.

The fluid retention barrel 12 b of the fluid injector 12 is alreadyfilled with a fluid (e.g., medicinal solution) to be injected into theskin tissue of an organism (e.g., human being). After removing the cap,not shown, the piston member 12 c is slightly pushed to discharge thefluid retained by the fluid retention barrel 12 b into the fluidretention space of the body 10 b of the multi-microneedle device 10 andthe microscopic fluid injection channels of the plurality ofmicroneedles 10 c of the multi-microneedle device 10. Thus, the spaceand the channels are filled with the fluid.

After that, keeping the state of holding the fluid injector retentioncylinder 22, the user presses, as shown in FIG. 1, the skin contactsurface 16 d in one-end face of the outer cylinder 16 against an exposedskin SK at a desired position of an organism (e.g., human being).

In this case, the exposed skin SK at the desired position is pushedinward by the skin contact surface 16 d of the one-end face of the outercylinder 16.

The multi-microneedle device 10 in this case is at the first protrudingposition with the plurality of microneedles 10 c being externallyprotruded by the first distance from the one-end opening 16 a of theouter cylinder 16. As shown in FIG. 1, these microneedles 10 c are thenreliably thrust into the exposed skin SK at the desired position, theskin SK being pushed by the skin contact surface 16 d of the one-endface of the outer cylinder 16 and residing in the area enclosed by theone-end opening 16 a of the one-end face of the outer cylinder 16.

In this case, the skin tissue in the area at the desired position of theexposed skin SK is in a state of having lost the elasticity to someextent.

Then, while the fluid injector retention cylinder 22 is being held, therotational operation member 16 e of the outer cylinder 16 is operatedfor rotation by a predetermined amount of rotation in a given rotationdirection. Thus, as shown in FIG. 2, the rotational-linear movementconversion mechanism 20 of the selective movement mechanism 18 causesoutward movement to the fluid injector 12 fixed to the multi-microneedledevice 10, the intermediate member 18 a fixed to the fluid injector 12via the multi-microneedle device 10, and the fluid injector retentioncylinder 22 fitted to the intermediate member 18 a as mentioned above,relative to the outer cylinder 16 from the desired position of thesurface of the skin SK by a predetermined distance along thelongitudinal center line of the outer cylinder 16.

In order to enable easy visual recognition of the predetermined distancefrom outside the operation tool 14, the peripheral wall of the outercylinder 16 may be calibrated in the outer surface thereof, covering arange in which an end face of the fluid injector retention cylinder 22moves, the end face being on the side of the outer cylinder 16.

As a result, the fluid injector 12 can be moved to the second protrudingposition at which the plurality of microneedles 10 c of themulti-microneedle device 10 are protruded to the external space by thesecond distance, which is shorter than the first distance shown in FIG.1, from the one-end opening 16 a of the outer cylinder 16.

In this way, the multi-microneedle device 10 is moved from the firstprotruding position shown in FIG. 1 to the second protruding positionshown in FIG. 2. With this movement, the plurality of microneedles 10 care protruded by the second distance, which is shorter than the firstdistance, from the one-end opening 16 a of the outer cylinder 16.

At the desired position of the exposed skin SK, the plurality ofmicroneedles 10 c of the multi-microneedle device 10 that has been movedto the second protruding position, weaken the pressing force in the areaenclosed by the one-end opening 16 a of the outer cylinder 16. Then,restoring the elasticity, the skin in the area subserviently moves withthe plurality of microneedles 10 c. As a result of the movement, asshown in FIG. 2, the thrust of the plurality of microneedles 10 c in thearea is still maintained.

While the multi-microneedle device 10 is held at the second protrudingposition as described above and shown in FIG. 2, the user presses thepiston member 12 c of the fluid injector 12. As a result, the fluid thathas been filled in the fluid retention barrel 12 b of the fluid injector12, the fluid retention space of the body 10 b of the multi-microneedledevice 10, and the microscopic fluid injection channels of the pluralityof microneedles 10 c as mentioned above can be easily and promptlyinjected, as indicated by the plurality of arrows in FIG. 2, into theskin tissue without leaking the fluid out of the skin SK, in the area atthe desired position of the exposed skin SK that has restored theelasticity as mentioned above.

In the case where a transparent material is used for forming the fluidinjector retention cylinder 22 of the operation tool 14, the outercylinder 16, the intermediate member 18 a, and the fluid retentionbarrel 12 b of the fluid injector 12, the user can easily visuallyrecognize the amount of injection of the fluid via the fluid injectionretention cylinder 22, the outer cylinder 16, and the intermediatemember 18 a of the operation tool 14, and the fluid retention barrel 12b of the fluid injector 12.

In this way, the fluid can be injected from the fluid injector 12 intothe skin tissue in the area at the desired position of the exposed skinSK, via the plurality of microneedles 10 c of the multi-microneedledevice 10. After completing injection, the operation tool 14 is pulledapart from the desired position of the exposed skin SK. Concurrentlywith this, the plurality of microneedles 10 c of the multi-microneedledevice 10 are pulled away from the skin tissue in the area at thedesired position of the exposed skin SK.

In the foregoing embodiment, the user has pressed the piston member 12 cexternally exposed from the fluid injector 12 during the period when theplurality of microneedles 10 c of the multi-microneedle device 10 aremaintained at the second protruding position as shown in FIG. 2.However, the pressing of the piston member 12 c during this period canbe alternatively conducted by a fluid injector selective drive unit 30shown in FIGS. 1 and 2.

Such a fluid injector selective drive unit 30 can be detachably fixed toa portion in the outer peripheral surface of the fluid injectorretention cylinder 22 or the intermediate member 18 a, the portion beingopposite to the multi-microneedle device 10. Being fixed in this way,the fluid injector selective drive unit 30 is configured to selectivelypress an externally exposed end of the piston member 12 c as describedabove. Such a configuration may include a drive member, not shown, whichis brought into contact with the externally exposed end of the pistonmember 12 c, a biasing force source, not shown, that is provided to thedrive member and exerts a biasing force toward the external exposed endof the piston member 12 c, and a switch mechanism that allows thebiasing force source, not shown, to selectively generate a biasingforce.

More specifically, for example, the biasing force source, not shown, canbe selected from a compressing spring, or a tension spring, or anelastic material, or a source of supply of compressed gas includingcompressed air. Further, the switch mechanism can include a known latchmechanism, or a trigger type disengagement mechanism, or a push clasptype disengagement mechanism, which stops the movement of the drivemember, not shown, resisting the biasing force from the biasing forcesource, not shown, or can include a manually or electromagneticallydriven on-off valve which is able to selectively supply compressed gasthat contains compressed air from a source of supply to the drivemember, not shown.

Modification

Referring now to FIGS. 3 and 4, hereinafter is described a modificationof the operation tool 14 according to the first embodiment shown inFIGS. 1 and 2.

Most of the configuration of an operation tool 14′ of a firstmodification is similar to most of the configuration of the operationtool 14 according to the first embodiment shown in FIGS. 1 and 2.Accordingly, in the operation tool 14′ of the modification shown inFIGS. 3 and 4, the components similar to those of the operation tool 14according to the first embodiment shown in FIGS. 1 and 2 are designatedwith the same references, and detailed description of these componentsis omitted.

The operation tool 14′ of the modification is different from theoperation tool 14 according to the first embodiment in the length of anouter cylinder 16′ along its longitudinal center line.

The body 10 b of the multi-microneedle device 10 has a surface(hereinafter referred to as a tip surface) 10 d from which the pluralityof microneedles 10 c are protruded. In the present modification, thelength of the outer cylinder 16′ along its longitudinal center line isconfigured to satisfy the following. In the configuration, as shown inFIG. 3, the fluid injector 12, when it is located at a first protrudingposition in the fluid injector housing space 16 c of the outer cylinder16′, the plurality of microneedles 10 c of the multi-microneedle device10 are externally protruded from the one-end opening 16 a of the outercylinder 16′ by a first distance. While the fluid injector 12 is locatedat the first protruding position, the one-end opening 16 a of the outercylinder 16′ is positioned inward relative to the tip surface 10 d ofthe multi-microneedle device 10, in a direction along the longitudinalcenter line of the outer cylinder 16′. Further, in the configuration, asshown in FIG. 4, the fluid injector 12, when it is located at a secondprotruding position in the fluid injector housing space 16 c of theouter cylinder 16′, the plurality of microneedles 10 c of themulti-microneedle device 10 are protruded to an external space from theone-end opening 16 a of the outer cylinder 16′ by a second distancewhich is shorter than the first distance shown in FIG. 3. While thefluid injector 12 is located at the second protruding position, theone-end opening 16 a of the outer cylinder 16′ is positioned eitherbeing flush with or being protruded outward, relative to the tip surface10 d of the multi-microneedle device 10, in the direction along thelongitudinal center line of the outer cylinder 16′.

In FIG. 4, the fluid injector 12 is located in the fluid injectorhousing space 16 c of the outer cylinder 16′ such that the plurality ofmicroneedles 10 c of the multi-microneedle device 10 are located at thesecond protruding position. While the microneedles 10 c are located atthe second protruding position, the one-end opening 16 a of the outercylinder 16′ is positioned being protruded outward relative to the tipsurface 10 d of the multi-microneedle device 10, in the direction alongthe longitudinal center line of the outer cylinder 16′.

Referring now to FIGS. 3 and 4, hereinafter is described a procedure ofinjecting a fluid (e.g., medicinal solution) retained by the fluidinjector 12, which uses the multi-microneedle device 10, into a desiredportion of the skin tissue of the exposed skin of an organism (e.g.,human being in the present embodiment) by operating the fluid injector12 by means of the operation tool 14′ which is based on the foregoingmodification.

The fluid retention barrel 12 b of the fluid injector 12, which isalready filled with a fluid (e.g., medicinal solution) is detachablymounted to the outlet nozzle mounting nozzle 10 a of themulti-microneedle device 10 which is located at the first protrudingposition shown in FIG. 3. The piston member 12 c is slightly pushed tofill, in advance, the fluid retained by the fluid retention barrel 12 binto the fluid retention space of the body 10 b of the multi-microneedledevice 10 and the microscopic fluid injection channels of the pluralityof microneedles 10 c of the multi-microneedle device 10. While the fluidis being filled into the fluid retention space and the microscopic fluidinjection channels, the user, in a state of holding the fluid injectionretention cylinder 22, presses the tip surface 10 d of themulti-microneedle device 10, as shown in FIG. 3, against the exposedskin SK at a desired position of an organism (e.g., human being).

As a result, the plurality of microneedles 10 c of the multi-microneedledevice 10 are reliably and deeply thrust into the exposed skin SK at thedesired position of the organism (e.g., human being). In this case, theexposed skin SK at the desired position is pressed inward by the tipsurface 10 d of the body 10 b of the multi-microneedle device 10.

Then, while the fluid injector retention cylinder 22 is being held, therotational operation member 16 e of the outer cylinder 16′ is operatedto rotate the outer cylinder 16′ by a predetermined amount of rotationin a given rotation direction. Thus, as shown in FIG. 4, therotational-linear movement conversion mechanism 20 of the selectivemovement mechanism 18 causes outward movement to the fluid injector 12fixed to the multi-microneedle device 10, the intermediate member 18 afixed to the fluid injector 12 via the multi-microneedle device 10, andthe fluid injector retention cylinder 22 fitted to the intermediatemember 18 a as mentioned above, from the desired position of the surfaceof the skin SK by a predetermined distance along the longitudinal centerline of the outer cylinder 16′.

In order to enable easy visual recognition of the predetermined distancefrom outside the operation tool 14′, the peripheral wall of the outercylinder 16′ may be calibrated in the outer surface thereof, covering arange in which an end face of the fluid injector retention cylinder 22moves, the end face being on the side of the outer cylinder 16.

As a result, the fluid injector 12 can be moved to the second protrudingposition at which the plurality of microneedles 10 c of themulti-microneedle device 10 are protruded to the external space by thesecond distance, which is shorter than the first distance shown in FIG.3, from the one-end opening 16 a of the outer cylinder 16′.

At the desired position of the exposed skin SK, the plurality of tomicroneedles 10 c of the multi-microneedle device 10, which have beenmoved to the second protruding position, weaken the pressing force inthe area enclosed by the one-end opening 16 a of the outer cylinder 16′.Then, restoring the elasticity, the skin in the area subserviently moveswith the plurality of microneedles 10 c. As a result of the movement, asshown in FIG. 4, the thrust of the plurality of microneedles 10 c in thearea is still maintained.

While the multi-microneedle device 10 is held at the second protrudingposition as described above and shown in FIG. 4, the user presses thepiston member 12 c of the fluid injector 12. As a result, the fluid thathas been filled in the fluid retention barrel 12 b of the fluid injector12, the fluid retention space of the body 10 b of the multi-microneedledevice 10, and the microscopic fluid injection channels of the pluralityof microneedles 10 c as mentioned above can be easily and promptlyinjected, as indicated by the plurality of arrows in FIG. 4, into theskin tissue without leaking the fluid out of the skin SK, in the area atthe desired position of the exposed skin SK that has restored theelasticity as mentioned above.

In the case where a transparent material is used for forming the fluidinjector retention cylinder 22 of the operation tool 14′, the outercylinder 16′, the intermediate member 18 a, and the fluid retentionbarrel 12 b of the fluid injector 12, the user can easily visuallyrecognize the amount of injection of the fluid via the fluid injectionretention cylinder 22 of the operation tool 14′, the outer cylinder 16′,the intermediate member 18 a, and the fluid retention barrel 12 b of thefluid injector 12.

In this way, the fluid can be injected from the fluid injector 12 intothe skin tissue in the area at the desired position of the exposed skinSK via the plurality of microneedles 10 c of the multi-microneedledevice 10. After completing injection, the operation tool 14′ is pulledapart from the desired position of the exposed skin SK. Concurrentlywith this, the plurality of microneedles 10 c of the multi-microneedledevice 10 are pulled away from the skin tissue in the area at thedesired position of the exposed skin SK.

In the foregoing modification as well, the user has pressed the pistonmember 12 c externally exposed from the fluid injector 12 during theperiod when the plurality of microneedles 10 c of the multi-microneedledevice 10 are maintained at the second protruding position as shown inFIG. 4. However, the pressing of the piston member 12 c during thisperiod can be alternatively conducted by the fluid injector selectivedrive unit 30 shown in FIGS. 3 and 4, similar to the first embodimentshown in FIGS. 1 and 2.

In each of the operation tool 14 of the first embodiment describedreferring to FIGS. 1 and 2, and the operation tool 14′ of themodification described referring to FIGS. 3 and 4, the external threadedportion 20 b of the rotational-linear movement conversion mechanism 20is not directly formed in the outer peripheral surface of the fluidretention barrel 12 b of the fluid injector 12, but, instead, is formedin the outer surface of the intermediate member 18 a which is fixed tothe fluid retention barrel 12 b via the multi-microneedle device 10 towhich the fluid retention barrel 12 b is detachably connected. However,according to the concept of the present invention, the intermediatemember 18 may be omitted, as a matter of course, to directly form theexternal threaded portion 20 b of the rotational-linear movementconversion mechanism 20 on the outer peripheral surface of the fluidretention barrel 12 b of the fluid injector 12.

In this case, the fitting groove 22 a of the fluid injector retentioncylinder 22 may be configured such that a finger flange at the other endof the outer peripheral wall of the fluid retention barrel 12 b of thefluid injector 12 is fitted to the fitting groove 22 a. With thisconfiguration, the fluid injector retention cylinder 22 can be movedalong the longitudinal center line of the fluid retention barrel 12 b(i.e. the longitudinal center line of the outer cylinder 16) or can berotated about the longitudinal center line, integrally with the fluidretention barrel 12 b of the fluid injector 22.

Further, use of the rotational-linear movement conversion mechanism 20enables control over the thrust depth of the plurality of microneedles10 c of the multi-microneedle device 10 with respect to the desiredposition of the skin SK in terms of a millimeter unit or asub-millimeter unit.

When intradermal injection is conducted by means of a syringe that usesa multi-microneedle device, a fluid (e.g., medicinal solution) to beused for the intradermal injection is charged in advance into thesyringe barrel of the syringe via the fluid outlet nozzle of the syringebarrel. Then, the outlet nozzle mounting nozzle of the multi-microneedledevice is detachably mounted to the fluid outlet nozzle of the syringebarrel. After that, the piston member of the syringe is slightly pushedto push the air in the fluid retention space of the multi-microneedledevice and in the individual microscopic fluid injection channels of theplurality of microneedles out of the syringe barrel, thereby filling thefluid in the fluid retention space and the microscopic fluid injectionchannels of the plurality of microneedles of the multi-microneedledevice.

Then, the skin contact surface of the body of the multi-microneedledevice is pressed against a desired portion of an exposed skin of anorganism (e.g., human being). With this pressing, the plurality ofmicroneedles on the skin contact surface are thrust into the skin tissuein the desired portion of the exposed skin of the organism (e.g., humanbeing). When the piston of the syringe is pushed subsequently, the fluidfrom the syringe barrel is injected into the skin tissue in the desiredportion of the exposed skin of the organism (e.g., human being) via thefluid retention space and the microscopic fluid injection channels ofthe plurality of microneedles of the multi-microneedle device.

When intradermal injection is conducted by means of a syringe that usesa multi-microneedle device, the piston member of the syringe is pushed,in a state where the skin contact surface of the body of themulti-microneedle device is pressed against a desired portion of theexposed skin of an organism (e.g., human being). In this case, thedesired portion of the exposed skin is loaded with not only a pressurefrom the skin contact surface of the body of the multi-microneedledevice, but also a force of pressing the piston of the syringe. As aresult, the skin tissue in the desired portion of the exposed skin loseselasticity to some extent. For this reason, not all of the fluid (e.g.,medicinal solution) can be injected from the plurality of microneedlesinto the desired portion of the skin tissue when intradermal injectionis conducted by means of a syringe that uses a multi-microneedle device.Therefore, the fluid is leaked onto the surface of the desired portionof the skin, or comparatively a long time is taken for injecting all ofa desired amount of the fluid into the skin tissue in the desiredportion.

The present invention has been made in light of the circumstances setforth above and has as its object to provide an operation tool, i.e. aninstrument for operating a fluid injector that uses a multi-microneedledevice, which easily and reliably enables any person to inject, in ashort time, all of a desired amount of a fluid in a fluid injector, suchas a syringe, that uses the multi-microneedle device, into a skin tissuein a desired portion, in conducting intradermal injection in the skintissue in the desired portion by means of the fluid injector, and whichcan be simply configured at low cost.

In order to achieve the object of the invention mentioned above, aninstrument for operating a fluid injector that uses a multi-microneedledevice, according to a concept of the present invention, that is, anoperation tool for a fluid injector that uses a multi-microneedledevice, is characterized in that the instrument includes:

an outer cylinder that has a one-end opening and an other-end opening,and a fluid injector housing space that extends between the one-endopening and the other-end opening and movably holds the fluid injectorthat uses the multi-microneedle device, along a longitudinal center lineof the fluid injector; and

a selective movement mechanism that moves the fluid injector between afirst protruding position and a second protruding position in the fluidinjector housing space of the outer cylinder, the first protrudingposition allowing a plurality of microneedles of the multi-microneedledevice to protrude to an external space by a first distance from theone-end opening of the outer cylinder, the second protruding positionallowing the plurality of microneedles of the multi-microneedle deviceto protrude the external space by a second distance that is shorter thanthe first distance from the one-end opening of the outer cylinder,wherein:

a fluid is discharged at the second protruding position from the fluidinjector via the plurality of microneedles of the multi-microneedledevice; and

the selective movement mechanism includes a rotational-linear movementconversion mechanism that is interposed between the outer cylinder andthe fluid injector, and moves the fluid injector between the firstprotruding position and the second protruding position along alongitudinal center line of the outer cylinder, in conformity with adirection and amount of rotation of the outer cylinder relative to thefluid injector.

In the instrument for operating a fluid injector that uses amulti-microneedle device, according to a concept of the presentinvention characterized by the above configuration:

The fluid injector is moved between the first protruding position andthe second protruding position by means of the selective movementmechanism. In this case, the fluid injector that uses themulti-microneedle device is movably held in the fluid injector housingspace extending between the one-end opening and the other-end opening ofthe outer cylinder, along the longitudinal center line of the fluidinjector. The first protruding position allows the plurality ofmicroneedles of the multi-microneedle device to protrude to an externalspace by a first distance from the one-end opening of the outercylinder. The second protruding position allows the plurality ofmicroneedles of the multi-microneedle device to protrude to the externalspace by a second distance, which is shorter than the first distance,from the one-end opening. Thus, at the second protruding position, thefluid is discharged from the fluid injector via the plurality ofmicroneedles of the multi-microneedle device.

The first protruding position can contribute to well thrusting theplurality of microneedles of the multi-microneedle device into a skintissue at the desired position.

In this case, the plurality of microneedles of the multi-microneedledevice applies a pressing force to the exposed skin at a desiredposition of an organism and the pressing force impairs the elasticity ofthe exposed skin at the desired position.

Then, the second protruding position can contribute to mitigating thepressing force applied by the plurality of microneedles of themulti-microneedle device to the exposed skin at the desired position ofthe organism. In other words, the elasticity is restored in the skintissue of the exposed skin at the desired position. This tendency ismore emphasized when the one-end opening of the outer cylinder is incontact with the exposed skin at the desired position.

Then, at the second protruding position, the fluid is discharged fromthe fluid injector via the plurality of microneedles of themulti-microneedle device. Thus, the fluid discharged from the pluralityof microneedles is promptly injected into the skin tissue of the exposedskin at the desired position of the organism.

Moreover, by operating the selective movement mechanism, anyone caneasily and reliably move the fluid injector that uses themulti-microneedle device, from the first protruding position to thesecond protruding position relative to the outer cylinder.

The instrument for operating a fluid injector that uses amulti-microneedle device is based on the invention characterized by theconfiguration as described above. Using such an instrument, whenconducting intradermal injection in a skin tissue at a desired positionby means of a fluid injector, such as a syringe, anyone can easily andreliably inject, in a short time, all of a desired amount of a fluid inthe fluid injector into the skin tissue at the desired position.

In addition, the selective movement mechanism includes therotational-linear movement conversion mechanism which is interposedbetween the outer cylinder and the fluid injector to move the fluidinjector from the first protruding position to the second protrudingposition along a longitudinal center line of the outer cylinder, inconformity with the direction and amount of the rotation of the outercylinder relative to the fluid injector.

Such a selective movement mechanism can be provided at low cost with asimple configuration.

DESCRIPTION OF REFERENCE NUMERALS

10 . . . Multi-microneedle device, 10 a . . . Outlet nozzle mountingnozzle, 10 b . . . Body, 10 c . . . Microneedles, 10 d . . . Tipsurface, 12 . . . Fluid injector, 12 a . . . Fluid outlet nozzle, 12 b .. . Fluid retention barrel, 12 c . . . Piston member, 14 . . . Operationtool, 16 . . . Outer cylinder, 16 a . . . One-end opening, 16 b . . .Other-end opening, 16 c . . . Fluid injector housing space, 16 d . . .Skin contact surface, 16 e . . . Rotational operation member, 18 . . .Selective movement mechanism, 18 a . . . Intermediate member, 18 b . . .Engagement projection, 20 . . . Rotational-linear movement conversionmechanism, 20 a . . . Internal threaded portion, 20 b . . . Externalthreaded portion, 22 . . . Fluid injector retention cylinder, 22 a . . .Fitting groove, SK . . . Skin;

14′ . . . Operation tool, 16′ . . . Outer cylinder

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

What is claimed is:
 1. An operation tool, comprising: an outer cylinderhaving a first open end, a second open end, and a cylinder body extendedbetween the first open end and the second open end, the cylinder bodybeing formed such that a fluid injector having a multi-microneedledevice is movable in the cylinder body along a longitudinal center lineof the fluid injector; a selective movement mechanism configured to movethe fluid injector between a first protruding position and a secondprotruding position in the cylinder body of the outer cylinder; and afluid injector retention cylinder positioned on an outer surface of aperipheral wall of the outer cylinder and connected by at least oneengagement projection of the selective movement mechanism fitted to atleast one groove of the fluid injector retention cylinder such that thefluid injector retention cylinder is rotatable together with the fluidinjector about a longitudinal center line of the outer cylinder andmovable along the longitudinal center line, relative to the outersurface of the peripheral wall of the outer cylinder, wherein theselective movement mechanism is configured such that, when the fluidinjector is at the first protruding position, a plurality ofmicroneedles of the multi-microneedle device is protruded out to a firstdistance from the first open end, and that when the fluid injector is atthe second protruding position to discharge a fluid from the fluidinjector via the microneedles, the microneedles are protruded out to asecond distance from the first open end, the second distance beingshorter than the first distance, and the selective movement mechanismincludes a rotational-linear movement conversion mechanism which isinterposed between the outer cylinder and the fluid injector, andconfigured to move the fluid injector between the first protrudingposition and the second protruding position along the longitudinalcenter line of the outer cylinder based on a direction and an amount ofrotation of the outer cylinder relative to the fluid injector.
 2. Theoperation tool according to claim 1, wherein the multi-microneedledevice has a surface from which the microneedles are protruded, and theselective movement mechanism is configured such that, when the fluidinjector is at the first protruding position, the first open end of theouter cylinder is positioned outward, relative to the surface of themulti-microneedle device, in a direction along the longitudinal centerline of the outer cylinder, and that when the fluid injector is at thesecond protruding position, the first open end of the outer cylinder ispositioned further outward than when the fluid injector is at the firstprotruding position, relative to the surface of the multi-microneedledevice, in a direction along the longitudinal center line of the outercylinder.
 3. The operation tool according to claim 2, furthercomprising: a fluid injector selective drive unit configured toselectively drive the fluid injector to discharge the fluid held in thefluid injector, via the multi-microneedle device.
 4. The operation toolaccording to claim 2, wherein the rotational-linear movement conversionmechanism includes an internal threaded portion which is formed on aninner surface of a peripheral wall of the outer cylinder and positionedto threadably engage with an external threaded portion of the fluidinjector.
 5. The operation tool according to claim 4, furthercomprising: a fluid injector selective drive unit configured toselectively drive the fluid injector to discharge the fluid held in thefluid injector, via the multi-microneedle device.
 6. The operation toolaccording to claim 1, wherein the multi-microneedle device has a surfacefrom which the microneedles are protruded, and the selective movementmechanism is configured such that, when the fluid injector is at thefirst protruding position, the first open end of the outer cylinder ispositioned inward, relative to the surface of the multi-microneedledevice, in a direction along the longitudinal center line of the outercylinder, and that when the fluid injector is at the second protrudingposition, the first open end of the outer cylinder is positioned eitherbeing flush with or being protruded outward, relative to the surface ofthe multi-microneedle device, in the direction along the longitudinalcenter line of the outer cylinder.
 7. The operation tool according toclaim 6, further comprising: a fluid injector selective drive unitconfigured to selectively drive the fluid injector to discharge thefluid held in the fluid injector, via the multi-microneedle device. 8.The operation tool according to claim 6, wherein the rotational-linearmovement conversion mechanism includes an internal threaded portionwhich is formed on an inner surface of a peripheral wall of the outercylinder and positioned to threadably engage with an external threadedportion of the fluid injector.
 9. The operation tool according to claim8, further comprising: a fluid injector selective drive unit configuredto selectively drive the fluid injector to discharge the fluid held inthe fluid injector, via the multi-microneedle device.
 10. The operationtool according to claim 1, further comprising: a fluid injectorselective drive unit configured to selectively drive the fluid injectorto discharge the fluid held in the fluid injector, via themulti-microneedle device.
 11. The operation tool according to claim 1,wherein the rotational-linear movement conversion mechanism includes aninternal threaded portion which is formed on an inner surface of aperipheral wall of the outer cylinder and positioned to threadablyengage with an external threaded portion of the fluid injector.
 12. Theoperation tool according to claim 11, further comprising: a fluidinjector selective drive unit configured to selectively drive the fluidinjector to discharge the fluid held in the fluid injector, via themulti-microneedle device.